What Tornado Alley’s eastward shift could mean for Dayton

The recent tornadoes that caused destruction across the Dayton region could be part of an eastward shifting ‘Tornado Alley’ into the Midwest and Southeast, including Ohio, experts say.

Several states are seeing a growing number of tornadoes in what has become the “Dixie Alley,” according to four decades worth of data studied by Northern Illinois University and the National Severe Storms Laboratory. Meanwhile Texas, Oklahoma and the Great Plains are seeing a declining number of twisters.

The traditional Tornado Alley still has more tornadoes than other parts of the country, but Ohio, Indiana, Illinois, Mississippi, Louisiana, Kentucky and Missouri are among the states seeing more tornadoes, including in the Miami Valley that saw 15 tornadoes ranging from EF0 to EF4 rip through neighborhoods destroying homes and businesses on Memorial Day.

Those tornadoes represent weather, not necessarily climate — the equivalent of a mood rather than personality, said Victor Gensini, one of the authors of the study.

“It’s hard to say for sure that the tornadoes that just happened in Dayton were because of the shift, but it is certainly consistent with some of the research that we’ve been doing that shows this eastward movement of the greatest frequency of tornadoes,” he said.

Severe thunderstorms with tornadoes, hail and high winds cause an average of $5.4 billion in damage each year in the United States and resulted in 600 related deaths in 2011, according to the study. The economic losses could continue to grow in upcoming years as risk and exposure increase disaster potential.

“This shift to the east is impacting more cities and higher populated areas,” said Storm Center 7 Chief Meteorologist McCall Vrydaghs. “Tornado Alley, right now, yes people live there, but these are not your big metro areas. When you start to shift it to the east, then you’re getting into where more people live and that can be much more dangerous to life loss.”

Metro areas such as Chicago, Indianapolis and Dayton that are in the shifting tornado belt are also growing, and as the cities get bigger, so does the potential for more damage, Gensini said. Especially in Kentucky, Tennessee and further south, more than 60% of the homes in some counties are mobile homes that could be destroyed by the lowest EF0 tornado.

It’s unclear why the alley is shifting east, Gensini said. It could be natural or a result of human influences on the climate.

“It’s a reminder for everybody that Ohio is not immune to tornado events. Ohio sees significant tornadoes and they’re not as rare there as people might think. This event in 10 years will be forgotten or the next generation will come up without really knowing what tornado happened when,” Gensini said. “If you forget history, forget the past, you kind of forget about what could happen in the future, so it’s a reminder that people need not be complacent in Dayton.”

The Miami Valley remains in the season where tornadoes are most likely to happen, Vrydaghs said. May through July marks an increased chance for storms.

May was also the second wettest month in the United States since the National Centers for Environmental Information began tracking in 1895. In the Miami Valley, ground saturation has been high for months stemming back to increased rainfall across more days last fall, which has formed potential for flash floods during any thunderstorm, Vrydaghs said.

“You have to take every individual tornado seriously…a little pebble flying at 70 mph is like a bullet,” she said. “So it doesn’t matter if it’s small or big, you need to take the same precautions.”